The present invention relates to the manufacture of razor blades and more particularly to the manufacture of a razor blade having a coating of polymeric material disposed on the edge surfaces thereof.
In the prior art, it is known to manufacture razor blades having various coatings which have been developed to provide the blades with a protection against atmospheric conditions as well as contact with various materials during storage or the shaving process which materials would tend to degrade the basic material of the blade.
In addition to the protection of the stainless steel, or other material, from which the blade is manufactured, the various coating supplied to the blade edges have been formulated with an attempt to eliminate the undesirable effects which occur in the shaving process that may cause irritation to the skin of the blade user.
In order to accomplish the above, blades have been treated by the coating of a polymeric material to the surface of the blade cutting edge by means of a sintering process. Generally, the process of applying the polymer material to the razor blade is accomplished by application of the polymeric material, in solution, to the blade and heating the blade in an oxygen-free environment causing the polymeric material to become sintered to the blade edge surface. Heating of the blade to produce the sintering has, in general, been accomplished by infra-red or resistance heating of the blade to a temperature in a range of between 200.degree. C. to 400.degree. C. Various examples of such a process are disclosed in U.S. Pat. No. 3,224,900 issued to Creamer et al.
It is an object of the present invention to provide an improvement to the prior art process of applying a coating of polymeric material to the edge surfaces of a razor blade through the introduction of induction heating in the manufacturing process.
Another object of the invention is to improve polymer to blade bonding by reducing the potential for gross cross-linking of excess polymer material.
Still a further object of the invention is to reduce the energy requirements for sintering of the polymeric material to the blade edge surface by the use of inductive sintering.